View Full Version : 1967 427 auto choke heat tube

02-17-2009, 07:44 PM
Twin 427 engines and neither choke will operate correctly. The heat tubes originating at the exhaust manifolds are clear but I can not draw heated air from the exhaust manifolds. Is there an easy way to open them up to breath? Is there a cut away diagram of the manifolds that would reveal the air flow circuit? Thanks for reviewing this request.

02-23-2009, 09:57 AM
"On my CC283 the heat tubes dead end at the manifold. My Carter Carb has a coiled metal spring that expands and contracts when heated and therefore activates the choke. Coil could be broken. http://www.marineengine.com/discus/clipart/sun.gif"

02-23-2009, 07:00 PM
The tubes terminate in my exhaust manifolds as well. The problem that I am having is that I can not draw any hot air out of the manifolds and the coils never get heated air in order to open correctly. I am wondering if there is a clogged vent that would let fresh air into the circuit?"

03-05-2009, 11:02 PM
"Best fix is to get a couple of the Holley electric choke elements. They fit the carter for size, but I think you have to reverse the thermostatic coil. Pretty easy to do. Then you don't have to deal with the clogged manifild heaters. If you are intent on using the exhaust heat, there used to be kits that drilled into the exhaust manifold for automotive use. Problem is to find a good place to drill on a marine manifold. Just a couple of thoughts. I've converted quite a few carbs to electric choke with good results."